diff mbox

[2/2,v4] i2c: exynos5: configure fifo_depth based on HSI2C module variant

Message ID 1391748195-12490-1-git-send-email-ch.naveen@samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

Naveen Krishna Chatradhi Feb. 7, 2014, 4:43 a.m. UTC 
fifo_depth of the HSI2C is not constant
Exynos5420 and Exynos5250 supports fifo_depth of 64bytes
Exynos5260 supports fifo_depth of 16bytes.

This patch configures the fifo_depth based on HSI2C modules version.

Signed-off-by: Naveen Krishna Chatradhi <ich.naveen@samsung.com>
[For finding out the difference and initial contribution]
Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
---
changes since v3:
use variant struct to handle the fifo depths

 drivers/i2c/busses/i2c-exynos5.c |   21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

Comments

Wolfram Sang March 12, 2014, 7:20 p.m. UTC | #1 
On Fri, Feb 07, 2014 at 10:13:15AM +0530, Naveen Krishna Chatradhi wrote:
> fifo_depth of the HSI2C is not constant
> Exynos5420 and Exynos5250 supports fifo_depth of 64bytes
> Exynos5260 supports fifo_depth of 16bytes.
> 
> This patch configures the fifo_depth based on HSI2C modules version.
> 
> Signed-off-by: Naveen Krishna Chatradhi <ich.naveen@samsung.com>
> [For finding out the difference and initial contribution]
> Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>

I know Tomasz said differently, but I prefer the patches squashed (and
the commit message extended).
Naveen Krishna Ch April 28, 2014, 6:35 a.m. UTC | #2 
Hello Wolfram,

On 13 March 2014 00:50, Wolfram Sang <wsa@the-dreams.de> wrote:
> On Fri, Feb 07, 2014 at 10:13:15AM +0530, Naveen Krishna Chatradhi wrote:
>> fifo_depth of the HSI2C is not constant
>> Exynos5420 and Exynos5250 supports fifo_depth of 64bytes
>> Exynos5260 supports fifo_depth of 16bytes.
>>
>> This patch configures the fifo_depth based on HSI2C modules version.
>>
>> Signed-off-by: Naveen Krishna Chatradhi <ich.naveen@samsung.com>
>> [For finding out the difference and initial contribution]
>> Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
>
> I know Tomasz said differently, but I prefer the patches squashed (and
> the commit message extended).
Please accept my apologies for coming back late on this CL.
Will squash and fix the compilation error and submit.

Thanks,
>
diff mbox

Patch

diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c
index 12730d1..5c875c0 100644
--- a/drivers/i2c/busses/i2c-exynos5.c
+++ b/drivers/i2c/busses/i2c-exynos5.c
@@ -76,12 +76,6 @@ 
 #define HSI2C_RXFIFO_TRIGGER_LEVEL(x)		((x) << 4)
 #define HSI2C_TXFIFO_TRIGGER_LEVEL(x)		((x) << 16)
 
-/* As per user manual FIFO max depth is 64bytes */
-#define HSI2C_FIFO_MAX				0x40
-/* default trigger levels for Tx and Rx FIFOs */
-#define HSI2C_DEF_TXFIFO_LVL			(HSI2C_FIFO_MAX - 0x30)
-#define HSI2C_DEF_RXFIFO_LVL			(HSI2C_FIFO_MAX - 0x10)
-
 /* I2C_TRAILING_CTL Register bits */
 #define HSI2C_TRAILING_COUNT			(0xf)
 
@@ -455,7 +449,7 @@  static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id)
 		fifo_status = readl(i2c->regs + HSI2C_FIFO_STATUS);
 		fifo_level = HSI2C_TX_FIFO_LVL(fifo_status);
 
-		len = HSI2C_FIFO_MAX - fifo_level;
+		len = i2c->variant->fifo_depth - fifo_level;
 		if (len > (i2c->msg->len - i2c->msg_ptr))
 			len = i2c->msg->len - i2c->msg_ptr;
 
@@ -523,6 +517,7 @@  static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, int stop)
 	u32 i2c_auto_conf = 0;
 	u32 fifo_ctl;
 	unsigned long flags;
+	unsigned short trig_lvl;
 
 	i2c_ctl = readl(i2c->regs + HSI2C_CTL);
 	i2c_ctl &= ~(HSI2C_TXCHON | HSI2C_RXCHON);
@@ -533,13 +528,19 @@  static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, int stop)
 
 		i2c_auto_conf = HSI2C_READ_WRITE;
 
-		fifo_ctl |= HSI2C_RXFIFO_TRIGGER_LEVEL(HSI2C_DEF_TXFIFO_LVL);
+		trig_lvl = (i2c->msg->len > i2c->variant->fifo_depth) ?
+			(i2c->variant->fifo_depth * 3/4) : i2c->msg->len;
+		fifo_ctl |= HSI2C_RXFIFO_TRIGGER_LEVEL(trig_lvl);
+
 		int_en |= (HSI2C_INT_RX_ALMOSTFULL_EN |
 			HSI2C_INT_TRAILING_EN);
 	} else {
 		i2c_ctl |= HSI2C_TXCHON;
 
-		fifo_ctl |= HSI2C_TXFIFO_TRIGGER_LEVEL(HSI2C_DEF_RXFIFO_LVL);
+		trig_lvl = (i2c->msg->len > i2c->variant->fifo_depth) ?
+			(i2c->variant->fifo_depth * 1/4) : i2c->msg->len;
+		fifo_ctl |= HSI2C_TXFIFO_TRIGGER_LEVEL(trig_lvl);
+
 		int_en |= HSI2C_INT_TX_ALMOSTEMPTY_EN;
 	}
 
@@ -731,6 +732,8 @@  static int exynos5_i2c_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_clk;
 
+	i2c->variant = exynos5_i2c_get_variant(pdev);
+
 	exynos5_i2c_reset(i2c);
 
 	ret = i2c_add_adapter(&i2c->adap);